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Tuesday, July 30, 2013

Oracle OS Watcher Black Box

OS Watcher Black Box (oswbb) is a collection of UNIX shell scripts intended to collect and archive operating system and network metrics to aid support in diagnosing performance issues. 

oswbb operates as a set of background processes on the server and gathers OS data on a regular basis, invoking such Unix utilities as vmstat, netstat and iostat. oswbb can be downloaded from this note. 

oswbb consists of a series of shell scripts. OSWatcher.sh is the main controlling executive, which spawns individual shell processes to collect specific kinds of data, using Unix operating system diagnostic utilities. Control is passed to individually spawned operating system data collector processes, which in turn collect specific data, timestamp the data output, and append the data to pre-generated and named files. Each data collector will have its own file, created and named by the File Manager process.

Data collection intervals are configurable by the user, but will be uniform for all data collector processes for a single instance of the oswbb tool. For example, if oswbb is configured to collect data once per minute, each spawned data collector process will generate output for its respective metric, write data to its corresponding data file, then sleep for one minute (or other configured interval) and repeat. Because we are collecting data every minute, the files generated by each spawned processes will contain 60 entries, one for each minute during the previous hour. Each file will contain, at most, one hour of data. At the end of each hour, File Manager will wake up and copy the existing current hour file to an archive location, then create a new current hour file.

The File Manager ensures only the last hours of information are retained, where is a configurable integer defaulting to 48. File Manager will wake up once per hour to delete files older than Nhours. At any time, the entire output file set will consist of one current hour file, plus archive files for each data collector process.

stoposwbb.sh will terminate all processes associated with oswbb, and is the normal, graceful mechanism for stopping the tool's operation.

oswbb invokes these distinct operating system utilities, each as a distinct background process, as data collectors. These utilities will be supported, or their equivalents, as available for each supported target platform.
  • ps
  • top
  • mpstat
  • iostat
  • netstat
  • traceroute
  • vmstat


oswbb is certified to run on the following platforms:
  • AIX
  • Tru64
  • Solaris
  • HP-UX
  • Linux

Installing oswbb

oswbb needs to be installed on each node, one installation per node. oswbb should be installed manually by using the following procedure:
NOTE: oswbb is available through MOS and can be downloaded as a tar file. The user then copies the file oswbb.tar to the directory where oswbb is to be installed and issues the following commands.
tar xvf oswbb.tar
A directory named oswbb is created which houses all the files associated with oswbb. oswbb is now installed.



Setting up oswbb

oswbb collects data and stores it to log files in an archive directory. 
By default, this directory is created under the oswbb directory where oswbb is installed. 
There are 2 options if you want to change this location to point to any other directory or device. 1. set the UNIX environment variable oswbb_ARCHIVE_DEST to the location desired before starting the tool 
or 
2. start oswbb by running the startoswbb.sh script located in the directory where oswbb is installed. This script accepts an optional 4th parameter which is the location where you want oswbb to write the the data it collects. 

If you use the optional 4th parameter you must also set the optional 3rd parameter which specifies the name of a compress or zip(gzip,compress, etc) utility. If you do not want to compress the files you can specify NONE as the 3rd parameter. See the startoswbb.sh for more details. Once oswbb is installed, scripts have been provided to start and stop the oswbb utility. When oswbb is started for the first time it creates the archive subdirectory, either in the default location under the oswbb directory or in an alternate location as specified above. The archive directory contains 7 subdirectories, one for each data collector. Data collectors exist for top, vmstat, iostat, mpstat, netstat, ps and an optional collector for tracing private networks. To turn on data collection for private networks the user must create an executable file in the oswbb directory named private.net. An example of what this file should look like is named Exampleprivate.net with samples for each operating system: solaris, linux, aix, hp, etc. in the oswbb directory. This file can be edited and renamed private.net or a new file named private.net can be created. This file contains entries for running the traceroute command to verify RAC private networks.

Exampleprivate.net entry on Solaris:

traceroute -r -F node1
traceroute -r -F node2

Where node1 and node2 are 2 nodes in addition to the hostnode of a 3 node RAC cluster. If the file private.net does not exist or is not executable then no data will be collected and stored under the oswprvtnet directory.

oswbb will need access to the OS utilities: top, vmstat, iostat, mpstat, netstat, and traceroute. These OS utilities need to be install on the system prior to running oswbb.  Execute permission on these utilities need to be granted to the user of oswbb.

Starting oswbb

To start the oswbb utility execute the startoswbb.sh shell script from the directory where oswbb was installed. This script has 2 arguments which control the frequency that data is collected and the number of hour's worth of data to archive.
ARG1 = snapshot interval in seconds.
ARG2 = the number of hours of archive data to store.
ARG3 = (optional) the name of a compress utility to compress each file automatically after it is created.
ARG4 = (optional) an alternate (non default) location to store the archive directory.
If you do not enter any arguments the script runs with default values of 30 and 48 meaning collect data every 30 seconds and store the last 48 hours of data in archive files.

Example 1: This would start the tool and collect data at default 30 second intervals and log the last 48 hours of data to archive files.

./startoswbb.sh

Example 2: This would start the tool and collect data at 60 second intervals and log the last 10 hours of data to archive files and automatically compress the files.

./startoswbb.sh 60 10 gzip

Example 3: This would start the tool and collect data at 60 second intervals and log the last 10 hours of data to archive files, compress the files and set the archive directory to a non-default location.

./startoswbb.sh 60 10 gzip /u02/tools/oswbb/archive

Example 4: This would start the tool and collect data at 60 second intervals and log the last 48 hours of data to archive files, NOT compress the files and set the archive directory to a non-default location.

./startoswbb.sh 60 48 NONE /u02/tools/oswbb/archive

This would start the tool, put the process in the background, enable to the tool to continue running after the session has been terminated, collect data at 60 second intervals, and log the last 10 hours of data to archive files.

Stopping oswbb

To stop the oswbb utility execute the stoposwbb.sh command from the directory where oswbb was installed. This terminates all the processes associated with the tool.

Example:

./stoposwbb.sh

Diagnostic Data Output

As stated above, when oswbb is started for the first time it creates the archive subdirectory under the oswbb installation directory. The archive directory contains 7 subdirectories, one for each data collector. These directories are named oswiostat, oswmpstat, oswnetstat, 

oswprvtnet, oswps, oswtop, and oswvmstat. One file per hour will be generated in each of the 7 OS utility subdirectories with the exception of oswprvtnet which is dependent on having private networks tracing configured. A new file is created at the top of each hour during the time that oswbb is running. The file will be in the following format:

__YY.MM.DD.HH24.dat

Details about each type of data file can be viewed by clicking on the below links:

oswiostat
oswmpstat
oswnetstat
oswprvtnet
oswps
oswtop
oswvmstat


oswiostat

_iostat_YY.MM.DD:HH24.dat
These files will contain output from the 'iostat' command that is obtained and archive by OSWatcher Black Box at specified intervals.  These files will only exist if 'iostat' is installed on the OS and if the oswbb user has privileges to run the utility.
The iostat command is used for monitoring system input/output device loading by observing the time the physical disks are active in relation to their average transfer rates. This information can be used to change system configuration to better balance the input/output load between physical disks and adapters.
The iostat utility is fairly standard across UNIX platforms, but really on useful for those platforms that support extended disk statistics: AIX, Solaris and Linux. Also each platform will have a slightly different version of the iostat utility. You should consult your operating system man pages for specifics. The sample provided below is for Solaris.
oswbb runs the iostat utility at the specified interval and stores the data in the oswiostat subdirectory under the archive directory. The data is stored in hourly archive files. Each entry in the file contains a timestamp prefixed by *** embedded in the iostat output. Notice there is one entry for each timestamp.
Sample iostat file produced by oswbb
extended device statistics
r/sw/skr/skw/swaitactvwsvc_tasvc_t%w%bdevice
0.00.30.02.10.00.03.40.800c0t0d0
0.02.10.112.90.00.00.60.400c0t2d0
0.00.00.00.00.00.00.00.000fd0
2.91.2240.81.50.00.10.013.305c1t0d0
1.10.818.08.80.00.00.15.901c1t1d0
0.00.00.00.00.00.00.00.000c0t1d0

Field Descriptions

The iostat output contains summary information for all devices.

FieldDescription
r/sShows the number of reads/second
w/sShows the number of writes/second
kr/sShows the number of kilobytes read/second
kw/sShows the number of kilobytes written/second
waitAverage number of transactions waiting for service (queue length)
actvAverage number of transactions actively being serviced
wsvc_tAverage service time in wait queue, in milliseconds
asvc_tAverage service time of active transactions, in milliseconds
%wPercent of time there are transactions waiting for service
%bPercent of time the disk is busy
deviceDevice name

What to look for
  • Average service times greater than 20msec for long duration.
  • High average wait times.

oswmpstat

_mpstat_YY.MM.DD:HH24.dat

These files will contain output from the 'mpstat' command that is obtained and archive by OSWatcher Black Box at specified intervals.  These files will only exist if 'mpstat' is installed on the OS and if the oswbb user has privileges to run the utility.
The mpstat command collects and displays performance statistics for all logical CPUs in the system.

The mpstat utility is fairly standard across UNIX platforms. Each platform will have a slightly different version of the mpstat utility. You should consult your operating system man pages for specifics. The sample provided below is for Solaris.

oswbb runs the mpstat utility at the specified interval and stores the data in the oswmpstat subdirectory under the archive directory. The data is stored in hourly archive files. Each entry in the file contains a timestamp prefixed by *** embedded in the mpstat output. Notice there are 2 entries for each timestamp. You should always ignore the first entry as this entry is always invalid.

Sample mpstat file produced by oswbb
***Fri Jan 28 12:50:36 EST 2005
CPUminfmjfxcalintrithrcswicswmigrsmtxsrwsysclusrsyswtidl
0000483383118100064000100
0126800486382414420002902824068
0400479379144300096000100

Field Descriptions

FieldDescription
cpuProcessor ID
minfMinor faults
mifMajor Faults
xcalProcessor cross-calls (when one CPU wakes up another by interrupting it).
intrInterrupts
ithrInterrupts as threads (except clock)
cswContext switches
icswInvoluntary context switches
migrThread migrations to another processor
smtxNumber of times a CPU failed to obtain a mutex
srwNumber of times a CPU failed to obtain a read/write lock on the first try
sysclNumber of system calls
usrPercentage of CPU cycles spent on user processes
sysPercentage of CPU cycles spent on system processes
wtPercentage of CPU cycles spent waiting on event
idlPercentage of unused CPU cycles or idle time when the CPU is basically doing nothing

What to look for
  • Involuntary context switches (this is probably the more relevant statistic when examining performance issues.)
  • Number of times a CPU failed to obtain a mutex. Values consistently greater than 200 per CPU causes system time to increase.
  • xcal is very important, show processor migration

oswnetstat

_netstat_YY.MM.DD:HH24.dat

These files will contain output from the 'netstat' command that is obtained and archive by OSWatcher Black Box at specified intervals.  These files will only exist if 'netstat' is installed on the OS and if the oswbb user has privileges to run the utility.

The netstat command displays current TCP/IP network connections and protocol statistics.
The netstat utility is standard across UNIX platforms. Each platform will have a slightly different version of the netstat utility. You should consult your operating system man pages for specifics. The sample provided below is for Solaris.

oswbb runs the netstat utility at the specified interval and stores the data in the oswnetstat subdirectory under the archive directory. The data is stored in hourly archive files. Each entry in the file contains a timestamp prefixed by *** embedded in the netstat output.
The netstat utility has many command line flags, and the most commonly used to troubleshoot RAC is "ia(n)" for the interface level output and "s" for the protocol level statistics. The following are examples for the two different command parameters.

The command line options "-ain" have these effects:

OptionDescription
-aThe command output will use the logical names of the interface. It will also report the name of the IP address found through normal IP address resolution methods.
-iThis triggers the Interface specific statistics, the columns of which are outlined in table [bla-KR]
-nThis causes the output to use IP addresses instead of the resolved names

Example netstat file produced by oswbb:
Sample netstat file produced by oswbb
***Fri Jan 28 12:50:36 EST 2005
NameMtuNet/DestAddressIpktsIerrsOpktsOerrsCollisQueue
lo08232127.0.0.0127.0.0.12960650296065000
eri01500138.1.140.0138.1.140.96017624421919510
RAWIP
rawipInDatagrams=0rawipInErrors=0
rawipInCksumErrs=0rawipOutDatagrams=0
rawipOutErrors=0
UDP
udpInDatagrams=295719udpInErrors=0
udpOutDatagrams=295671udpOutErrors=0
TCP
tcpRtoAlgorithm=4tcpRtoMin=400
tcpRtoMax=60000tcpMaxConn=-1
tcpActiveOpens=27tcpPassiveOpens=21
tcpAttemptFails=6tcpEstabResets=0
tcpCurrEstab=15tcpOutSegs=691
tcpOutDataSegs=479tcpOutDataBytes=43028
tcpRetransSegs=0tcpRetransBytes=0
tcpOutAck=212tcpOutAckDelayed=83
tcpOutUrg=0tcpOutWinUpdate=0
tcpOutWinProbe=0tcpOutControl=85
tcpOutRsts=10tcpOutFastRetrans
tcpInSegs=915=0
tcpInAckSegs=489tcpInAckBytes=43023
tcpInDupAck=42tcpInAckUnsent=0
tcpInInorderSegs=477tcpInInorderBytes=40640
tcpInUnorderSegs=0tcpInUnorderBytes=0
tcpInDupSegs=0tcpInDupBytes=0
tcpInPartDupSegs=0tcpInPartDupBytes=0
tcpInPastWinSegs=0tcpInPastWinBytes=0
tcpInWinProbe=0tcpInWinUpdate=0
tcpInClosed=0tcpRttNoUpdate=0
tcpRttUpdate=462tcpTimRetrans=0
tcpTimRetransDrop=0tcpTimKeepalive=80
tcpTimKeepaliveProbe=0tcpTimKeepaliveDrop=0
tcpListenDrop=0tcpListenDropQ0=0
tcpHalfOpenDrop=0tcpOutSackRetrans=0
IPv4
ipForwarding=2ipDefaultTTL=255
ipInReceives=17858585ipInHdrErrors=0
ipInAddrErrors=0ipInCksumErrs=0
ipForwDatagrams=0ipForwProhibits=0
ipInUnknownProtos=0ipInDiscards=0
ipInDelivers=296623ipOutRequests=17624403
ipOutDiscards=0ipOutNoRoutes=827
ipReasmTimeout=60ipReasmReqds=0
ipReasmOKs=0ipReasmFails=0
ipReasmDuplicates=0ipReasmPartDups=0
ipFragOKs=0ipFragFails=0
ipFragCreates=0ipRoutingDiscards=0
tcpInErrs=0udpNoPorts=225722
udpInCksumErrs=0udpInOverflows=0
rawipInOverflows=0ipsecInSucceeded=0
ipsecInFailed=0ipInIPv6=0
ipOutIPv6=0ipOutSwitchIPv6=5
IPv6
ipv6Forwarding=2ipv6DefaultHopLimit=255
ipv6InReceives=0ipv6InHdrErrors=0
ipv6InTooBigErrors=0ipv6InNoRoutes=0
ipv6InAddrErrors=0ipv6InUnknownProtos=0
ipv6InTruncatedPkts=0ipv6InDiscards=0
ipv6InDelivers=0ipv6OutForwDatagrams=0
ipv6OutRequests=0ipv6OutDiscards=0
ipv6OutNoRoutes=0ipv6OutFragOKs=0
ipv6OutFragFails=0ipv6OutFragCreates=0
ipv6ReasmReqds=0ipv6ReasmOKs=0
ipv6ReasmFails=0ipv6InMcastPkts=0
ipv6OutMcastPkts=0ipv6ReasmDuplicates=0
ipv6ReasmPartDups=0ipv6ForwProhibits=0
udpInCksumErrs=0udpInOverflows=0
rawipInOverflows=0ipv6InIPv4=0
ipv6OutIPv4=0ipv6OutSwitchIPv4=0
ICMPv4
icmpInMsgs=17624914icmpInErrors=0
icmpInCksumErrs=0icmpInUnknowns=0
icmpInDestUnreachs=72icmpInTimeExcds=0
icmpInParmProbs=0icmpInSrcQuenchs=0
icmpInRedirects=0icmpInBadRedirects=0
icmpInEchos=17624842icmpInEchoReps=0
icmpInTimestamps=0icmpInTimestampReps=0
icmpInAddrMasks=0icmpInAddrMaskReps=0
icmpInFragNeeded=0icmpOutMsgs=17624920
icmpOutDrops=225716icmpOutErrors=0
icmpOutDestUnreachs=78icmpOutTimeExcds=0
icmpOutParmProbs=0icmpOutSrcQuenchs=0
icmpOutRedirects=0icmpOutEchos=0
icmpOutEchoReps=17624842icmpOutTimestamps=0
icmpOutTimestampReps=0icmpOutAddrMasks=0
icmpOutAddrMaskReps=0icmpOutFragNeeded=0
icmpInOverflows=0
ICMPv6
icmp6InMsgs=0icmp6InErrors=0
icmp6InDestUnreachs=0icmp6InAdminProhibs=0
icmp6InTimeExcds=0icmp6InParmProblems=0
icmp6InPktTooBigs=0icmp6InEchos=0
icmp6InEchoReplies=0icmp6InRouterSols=0
icmp6InRouterAds=0icmp6InNeighborSols=0
icmp6InNeighborAds=0icmp6InRedirects=0
icmp6InBadRedirects=0icmp6InGroupQueries=0
icmp6InGroupResps=0icmp6InGroupReds=0
icmp6InOverflows=0
icmp6OutMsgs=0icmp6OutErrors=0
icmp6OutDestUnreachs=0icmp6OutAdminProhibs=0
icmp6OutTimeExcds=0icmp6OutParmProblems=0
icmp6OutPktTooBigs=0icmp6OutEchos=0
icmp6OutEchoReplies=0icmp6OutRouterSols=0
icmp6OutRouterAds=0icmp6OutNeighborSols=0
icmp6OutNeighborAds=0icmp6OutRedirects=0
icmp6OutGroupQueries=0icmp6OutGroupResps=0
icmp6OutGroupReds=0
IGMP:
2490messages received
0messages received with too few bytes
0messages received with bad checksum
2490membership queries received
0membership queries received with invalid field(s)
0membership reports received
0membership reports received with invalid field(s)
0membership reports received for groups to which we belong
0membership reports sent

Field Descriptions:

The netstat output produced by oswbb contains 2 sections. The first section contains information about all the network interfaces. The second section contains information about per-protocol statistics.

Section 1: Netstat -ain

FieldDescription
nameDevice name of interface
MtuMaximum transmission unit
NetNetwork Segment Address
addressNetwork address of the device
ipktsInput packets
IerrsInput errors
opktsOutput Packets
OerrsOutput errors
collisCollisions
queueNumber in the Queue

Section 2: Protocol Statistics

The per-protocol statistics can be divided into several categories:
  • RAWIP (raw IP) packets
  • TCP packets
  • IPv4 packets
  • ICMPv4 packets
  • IPv6 packets
  • ICMPv6 packets
  • UDP packets
  • IGMP packet
Each protocol type has a specific set of measures associated with it. Network analysis requires evaluation of these measurements on an individual level and all together to examine the overall health of the network communications.
The TCP protocol is used the most in Oracle database and applications. Some implementations for RAC use UDP for the interconnect protocol instead of TCP. The statistics cannot be divided up on a per-interface basis, so these should be compared to the "-i" statistics above.

What to look for:

Section 1
The information in Section 1 will help diagnose network problems when there is connectivity but response is slow.
Values to look at:
  • Collisions (Collis)
  • Output packets (Opkts)
  • Input errors (Ierrs)
  • Input packets (Ipkts)
The above values will give information to workout network collision rates as follows:
Network collision rate = Output collision / Output packets
For a switched network, the collisions should be 0.1 percent or less (see the Cisco web site as a reference) of the output packets. Excessive collisions could lead to the switch port the interface is plugged into to segment, or pull itself off-line, amongst other switch-related issues.
For the input error statistics:
Input Error Rate = Ierrs / Ipkts.
If the input error rate is high (over 0.25 percent), the host is excessively dropping packets. This could mean there is a mismatch of the duplex or speed  settings of the interface card and switch.  It could also imply a failed patch cable.

If ierrs or oerrs show an excessive amount of errors, more information can be found by examination of the netstat -s output.

For Sun systems, further information about a specific interface can be found by using the "-k" option for netstat. The output will give fuller statistics for the device, but this option is not mentioned in the netstat man page.

Section 2

The information in Section 2 contains the protocol statistics.
Many performance problems associated with the network involve the retransmission of the TCP packets.
To find the segment retransmission rate:
%segment-retrans=(tcpRetransSegs / tcpOutDataSegs) * 100
To find the byte retransmission rate:
%byte-retrans = ( tcpRetransBytes / tcpOutDataBytes ) * 100
Most network analyzers report TCP retransmissions as segments (frames) and not in bytes.

oswprvtnet

_prvtnet_YY.MM.DD:HH24.dat

These files will contain output from the 'prvtnet' command that is obtained and archived by OSWatcher Black Box at specified intervals.  These files will only exist if 'prvtnet' is installed on the OS and if the oswbb user has privileges to run the utility.

Information about the status of RAC private networks should be collected. This requires the user to manually add entries for these private networks into the private.net file located in the base oswbb directory. Instructions on how to do this are contained in the README file.

oswbb uses the traceroute command to obtain the status of these private networks. Each operating system uses slightly different arguments to the traceroute command. Examples of the syntax to use for each operating system are contained in the sample Exampleprivate.net file located in the base oswbb directory. This will result in the output appearing differently across UNIX platforms. oswbb runs the private.net file at the specified interval and stores the data in the oswprvtnet subdirectory under the archive directory. The data is stored in hourly archive files. Each entry in the file contains a timestamp prefixed by *** embedded in the top output.

Sample file produced by oswbb
***Fri Jan 28 12:50:36 EST 2005
traceroute to celdecclu2.us.oracle.com (138.2.71.112): 1-30 hops
(initial packetsize = 1500)
  1  celdecclu2.us.oracle.com (138.2.71.112) 1.95ms  2.92 ms 1.95 ms

What to Look For
  • Example 1:  Interface is up and responding:
traceroute to X.X.X.X, (X.X.X.X) 30 hops max, 1492 byte packets
1 X.X.X.X 1.015 ms 0.766 ms 0.755 ms

  • Example 2:  Target interface is not on a directly connected network, so validate that the address is correct or the switch it is plugged in is on the same VLAN (or other issue):
traceroute to X.X.X.X, (X.X.X.X) 30 hops max, 40 byte packets
traceroute: host X.X.X.X is not on a directly-attached network

  • Example 3:  Network is unreachable:
traceroute to X.X.X.X, (X.X.X.X) 30 hops max, 40 byte packets
Network is unreachable


_ps_YY.MM.DD:HH24.dat

These files will contain output from the 'ps' command that is obtained and archive by OSWatcher Black Box at specified intervals.  These files will only exist if 'ps' is installed on the OS and if the oswbb user has privileges to run the utility.

The ps (process state) command list all the processes currently running on the system and provides information about CPU consumption, process state, priority of the process, etc. The ps command has a number of options to control which processes are displayed, and how the output is formatted. oswbb runs the ps command with the -elf option.

The ps command is fairly standard across UNIX platforms Each platform will have a slightly different version of the ps utility. You should consult your operating system man pages for specifics. The sample provided below is for Solaris.

oswbb runs the ps command at the specified interval and stores the data in the oswps subdirectory under the archive directory. The data is stored in hourly archive files. Each entry in the file contains a timestamp prefixed by *** embedded in the ps output.

Sample ps file produced by oswbb
***Wed Feb 2 09:26:54 EST 2005
FSUIDPIDPPIDCPRINIADDRSZWCHANSTIMETTYTIMECMD
19Troot0000SY?0Jan 31?0:13sched
8Sroot1004120?107?Jan 31?0:00/etc
19Sroot2000SY?0?Jan 31?0:00page
19Sroot3000SY?0?Jan 31?0:50fsflu
8Sroot355104120?232?Jan 31?0:00/usr/
8Sroot29729604120?379?Jan 31?0:00htt_s
8Scedavis39138108920?301?Jan 31?0:00/usr/

Field Descriptions

FieldDescription
fFlags s State of the process
uidThe effective user ID number of the process
pidThe process ID of the process
ppidThe process ID of the parent process.
dProcessor utilization for scheduling (obsolete).
priThe priority of the process.
niNice value, used in priority computation.
addrThe memory address of the process.
szThe total size of the process in virtual memory, including all mapped files and devices, in pages.
wchanThe address of an event for which the process is sleeping (if blank, the process is running).
stimeThe starting time of the process, given in hours, minutes, and seconds.
ttyThe controlling terminal for the process (the message ?, is printed when there is no controlling terminal).
timeThe cumulative execution time for the process.
cmdThe command name process is executing.

What to look for
  • The information in the ps command will primarily be used as supporting information for RAC diagnostics. If for example, the status of a process prior to a system crash may be important for root cause analysis. The amount of memory a process is consuming is another example of how this data can be used.
oswtop

_top_YY.MM.DD:HH24.dat

These files will contain output from the 'top' command that is obtained and archive by OSWatcher at specified intervals.  These files will only exist if 'top' is installed on the OS and if the oswbb user has privileges to run the utility.
Top is a program that will give continual reports about the state of the system, including a list of the top CPU using processes. Top has three primary design goals:
  • provide an accurate snapshot of the system and process state,
  • not be one of the top processes itself,
  • be as portable as possible.
Each operating system uses a different version of the UNIX utility top. This will result in the top output appearing differently across UNIX platforms. You should consult your operating system man pages for specifics. The sample provided below is for Solaris.

oswbb runs the top utility at the specified interval and stores the data in the oswtop subdirectory under the archive directory. The data is stored in hourly archive files. Each entry in the file contains a timestamp prefixed by *** embedded in the top output.

Sample top file produced by oswbb
***Fri Jan 28 12:50:36 EST 2005
load averages: 0.11, 0.07, 0.06 12:50:36
136 processes: 133 sleeping, 2 running, 1 on cpu

Memory: 2048M real, 1061M free, 542M swap in use, 1605M swap free
PIDUSERNAMETHRPRINICESIZERESSTATETIMECPUCOMMAND
704cedavis16490346M276M  sleep222:333.51%java
362root159034M75M  sleep11:490.21%Xsun
20675cedavis1001584K1064K  cpu0:0019%top
20640cedavis1001904K1240K  sleep0:000.14%OSWatcher.sh
20657cedavis12001904K1240K  sleep0:000.14%oswsub.sh
16881cedavis1590199M159K  sleep23:040.10%oracle
20671cedavis1001904K1240K  run0:000.09%oswsub.sh
20653cedavis1001904K1240K  sleep0:000.09%OSWatcherFM.sh
20665cedavis1001904K1240K  sleep0:000.09%oswsub.sh
20672cedavis1001264K1031K  sleep0:000.09%iostat
20659cedavis11001904K1240K  sleep0:000.09%oswsub.sh
20661cedavis13001096K880Ksleep0:000.09%vmstat
20668cedavis1001904K1240Krun0:000.05%oswsub.sh
20674cedavis100968K624K  sleep0:000.05%sleep
20663cedavis12001080K864Ksleep0:000.05%mpstat

Field Descriptions
load averages: 0.11, 0.07, 0.06 12:50:36
This line displays the load averages over the last 1, 5 and 15 minutes as well as the system time. This is quite handy as top basically includes a timestamp along with the data capture.
Load average is defined as the average number of processes in the run queue. A runnable Unix process is one that is available right now to consume CPU resources and is not blocked on I/O or on a system call. The higher the load average, the more work your machine is doing.
The three numbers are the average of the depth of the run queue over the last 1, 5, and 15 minutes. In this example we can see that .11 processes were on the run queue on average over the last minute, .07 processes on average on the run queue over the last 5 minutes, etc. It is important to determine what the average load of the system is through benchmarking and then look for deviations. A dramatic rise in the load average can indicate a serious performance problem.
136 processes: 133 sleeping, 2 running, 1 on cpu
This line displays the total number of processes running at the time of the last update. It also indicates how many Unix processes exist, how many are sleeping (blocked on I/O or a system call), how many are stopped (someone in a shell has suspended it), and how many are actually assigned to a CPU. This last number will not be greater than the number of processors on the machine, and the value should also correlate to the machine's load average provided the load average is less than the number of CPUs. Like load average, the total number of processes on a healthy machine usually varies just a small amount over time. Suddenly having a significantly larger or smaller number of processes could be a warning sign.
Memory: 2048M real, 1061M free, 542M swap in use, 1605M swap free
The "Memory:" line is very important. It reflects how much real and swap memory a computer has, and how much is free. "Real" memory is the amount of RAM installed in the system, a.k.a. the "physical" memory. "Swap" is virtual memory stored on the machine's disk.
Once a computer runs out of physical memory, and starts using swap space, its performance deteriorates dramatically. If you run out of swap, you'll likely crash your programs or the OS.
Individual process fields
FieldDescription
PIDProcess ID of process
USERNAMEUsername of process
THRProcess thread PRI Priority of process
NICENice value of process
SIZETotal size of a process, including code and data, plus the stack space in kilobytes
RESAmount of physical memory used by the process
STATECurrent CPU state of process. The states can be S for sleeping, D for uninterrupted, R for running, T for stopped/traced, and Z for zombied
TIMEThe CPU time that a process has used since it started
%CPUThe CPU time that a process has used since the last update
COMMANDThe task's command name

What to Look For
  • Large run queue. Large number of processes waiting in the run queue may be an indication that your system does not have sufficient CPU capacity.
  • Process consuming lots of CPU. A process which is "hogging" CPU is always suspect. If this process is an oracle foreground process it's most likely running an expensive query that should be tuned. Oracle background process should not hog CPU for long periods of time.
  • High load averages. Processes should not be backed up on the run queue for extended periods of time.
  • Low swap space. This is an indication you are running low on memory.
oswvmstat

_vmstat_YY.MM.DD:HH24.dat

These files will contain output from the 'vmstat' command that is obtained and archive by OSWatcher Black Box at specified intervals.  These files will only exist if 'vmstat' is installed on the OS and if the oswbb user has privileges to run the utility.
The name vmstat comes from "report virtual memory statistics".  The vmstat utility does a bit more than this, though. In addition to reporting virtual memory, vmstat reports certain kernel statistics about processes, disk, trap, and CPU activity.
The vmstat utility is fairly standard across UNIX platforms. Each platform will have a slightly different version of the vmstat utility. You should consult your operating system man pages for specifics. The sample provided below is for Solaris.
oswbb runs the vmstat utility at the specified interval and stores the data in the oswvmstat subdirectory under the archive directory. The data is stored in hourly archive files. Each entry in the file contains a timestamp prefixed by *** embedded in the vmstat output.

Sample vmstat file produced by oswbb
***Fri Jan 28 12:50:36 EST 2005
procsmemorypagediskfaultscpu
rbwswapfreeremfpipofrdesrddf0s0insycsussyid
000176134412465201600000200038013649004195
00016439201086776331148581616003100044749661315153154
0001643872108672860000000000389147293200100

Field Descriptions
The vmstat output is actually broken up into six sections: procs, memory, page, disk, faults and CPU. Each section is outlined in the following table.

FieldDescription
PROCS
rNumber of processes that are in a wait state and basically not doing anything but waiting to run
bNumber of processes that were in sleep mode and were interrupted since the last update
wNumber of processes that have been swapped out by mm and vm subsystems and have yet to run
MEMORY
swapThe amount of swap space currently available free The size of the free list
PAGE
repage reclaims
mfminor faults
pikilobytes paged in
pokilobytes paged out
frkilobytes freed
deanticipated short-term memory shortfall (Kbytes)
srpages scanned by clock algorithm
DISK
BiDisk blocks sent to disk devices in blocks per second
FAULTS
InInterrupts per second, including the CPU clocks
SySystem calls
CsContext switches per second within the kernel
CPU
UsPercentage of CPU cycles spent on user processes
SyPercentage of CPU cycles spent on system processes
IdPercentage of unused CPU cycles or idle time when the CPU is basically doing nothing

What to look for

The following information should be used as a guideline and not considered hard and fast rules. The information documented below comes from Adrian Cockcroft's book, Sun Performance Tuning. Other operating systems like HP and Linux may have different thresholds.
  • Large run queue. Adrian Cockcroft defines anything over 4 processes per CPU on the run queue as the threshold for CPU saturation. This is certainly a problem if this last for any long period of time.
  • CPU utilization. The amount of time spent running system code should not exceed 30% especially if idle time is close to 0%.
  • A combination of large run queue with no idle CPU is an indication the system has insufficient CPU capacity.
  • Memory bottlenecks are determined by the scan rate (sr) . The scan rate is the pages scanned by the clock algorithm per second. If the scan rate (sr) is continuously over 200 pages per second then there is a memory shortage.
  • Disk problems may be identified if the number of processes blocked exceeds the number of processes on run queue.

1 comment:

Sridevi K said...

Regards
Sridevi Koduru (Senior Oracle Apps Trainer Oracleappstechnical.com)
LinkedIn profile - https://in.linkedin.com/in/sridevi-koduru-9b876a8b
Please Contact for One to One Online Training on Oracle Apps Technical, Financials, SCM, SQL, PL/SQL, D2K at training@oracleappstechnical.com | +91 - 9581017828.